Alternative (more efficient) Irrigation Systems David A. Bainbridge Author: A Guide to Desert and Dryland Restoration. Island Press. Retired, former Associate Professor, Alliant International University, San Diego, California

Water shortage! The problem of water shortage continues to grow - both locally and globally At the same time the need for restoration of dry lands and increasing food production from deserts and dry lands are both rising This led to my twenty five year adventure with alternative irrigation systems

Desertification

Desertification: now affects 1 billion people Northern Mexico

The First Step This is not a “new” problem so I started with an extensive literature search I also interviewed scientists and farmers who visited the Dry Lands Research Institute (at UC Riverside) Several interesting candidates emerged, and have proved useful!

Buried Clay Pot Irrigation One of the most studied, and very effective systems uses a buried clay pot full of water to irrigate plants The capillary flow of water is regulated by demand - so little water is wasted Highly recommended! For restoration, gardens, landscaping, farming

Simple and Effective Clay pots worked well even in the lowest, hottest desert in California Excellent for seedlings or for starting seeds or cuttings

Getting Started Regular red clay pots work well Seal the bottom hole with a cork or sealant Use a lid with a small hole drilled in it to capture rainwater

Place the pot Set the pot in the soil so the rim is above ground You don’t want the dirt and leaves to wash in Firm the soil around the pot -- and plant

A Long Tradition The agricultural text Fan Sheng-chih Shu, describes the use of buried clay pot irrigation in China more than 2,000 years ago Excerpts from this book provided my inspiration--writing does speak across time I later found work and use of clay pots in Iran, Pakistan, Mexico and other countries

Fewer Weeds Another great advantage of buried clay pots (and other deep watering systems) is reduced weed growth In one study weeds were cut 87% This means less work - and less wasted water! The second biggest problem for small farmers after water shortage is time shortage

Buried clay pots Buried clay pots have also proved to be very effective when saline water must be used - or when salt is a problem in the soil The steady moisture reduces salt buildup in the root zone and damage

Starting Cuttings Double clay pots are ideal for starting cuttings The inner pot is sealed and filled with water The moisture is maintained in the soil at an ideal level BCP are good for starting cuttings in the field as well

Deep Pipe Irrigation This method of irrigation was suggested by a traditional system from India - where water was placed in the hollow stem of a dead plant to water deeper in the soil Subsequent research found one study and one report from India This has been our best system for restoration work -- cheap, durable and very effective

Deep pipe installation The pipe may be about 14-16” long, 2” diameter, set vertically Small holes are drilled on the plant side below soil level A screen lid is glued on to protect wildlife

Deep pipe drip Where a drip system can be set up it can also be used in a deep pipe Smaller pipes can be used with the emitter inserted in the pipe

No waste Little water evaporates because the water is placed in the deep soil Little time is wasted because it is fast and easy to fill the pipe It works very well on slopes It develops large root systems

Excellent Results Survival is excellent with very little water Mesquite trees were started with a total of only 5 gallons of water in the first year - not five gallons a week or two gallons an hour

Wick Irrigation Wick systems were also described in reports from India Wicks were traditionally combined with clay pots to water orchard trees After trying several types of wicks I think this may be the next great thing!

Wick options Wicks can be used in a capillary form, where water is wicked from a reservoir to the plant through a raised section by capillary forces (as little as 20 ml day) Or in a gravity feed form, with the reservoir above the wick (a hose clamp can be used to adjust the flow rate)

Wick options Wick with clay pot With a riser tube in bottom hole Capillary wick from buried bottle in plastic tube

More wick options Half inch diameter gravity wick with a larger reservoir Installed with treeshelter and wire cage for jack rabbit protection Seedlings topped treeshelter at 3 weeks!

Wick Material The best material has been old, used mm solid braid nylon rope (5/16”-1/2”) Fresh nylon rope can be used if it is washed with detergent to remove oils - but it is not as good as old rope Fabric ca also be used Cotton was used in India, but tended to mold in my early tests

Porous Hose This system uses a vertically placed leaky or porous hose section It performs a bit like a clay pot--only it is cheaper and smaller These hoses are made of recycled rubber and hold up well It has to be high flow rate hose to work at low pressure head

Porous hose This can be fed by a bottle Or attached to a drip type line Both have worked reasonably well A fast rate hose is needed to work at low pressure

Tree shelter Watering into a tree shelter is also effective This can be done by hand or using a drip type system

Perforated Pipe Sub-irrigation can also be done with slotted drain pipe The pipe is laid deep in the soil and filled with water using a water truck Best for lines of plants - good for landscaping

Porous Capsules A modern adaptation of buried clay pot irrigation was developed in Brazil The clay is formed into a capsule that can be placed on a water line These worked well for me -- but were more costly to make

Types PC made by gluing two red clay pots together Clay pots made by a staffer using a beer bottle mold

Porous capsules These are easy to plumb in a system Or they can be gravity fed from a bottle or tank These are very efficient indeed A range of smaller porous irrigation systems are sold for container plants

Microcatchments A microcatchment is a specially contoured area with slopes and berms designed to increase rain runoff and concentrate it in small dams or depressions Rain falling on the catchment area drains into a planting basin where it infiltrates and is effectively "stored" in the soil profile Used for millennia - very effective if it rains!

A Microcatchment Microcatchments can be shaped to look more natural, but do entail disturbing the soil surface More appropriate in agriculture - but has worked well on restoration projects

Problems with drip Drip irrigation has been very effective in agriculture and is often the best choice, but we can do better for the hundreds of millions of farmers who cannot afford drip Water for drip must be filtered and pressurized and maintenance is critical It is also not as efficient as these alternatives - some may be 2-4 times more water efficient than surface drip

Drip problems Drip is not well suited for remote sites - due to animal damage Even when open water is nearby animals will chew on drip tubing Insect, root and salt clogging and other problems also occur regularly

The best system? It depends All have been very good Deep pipes have been most commonly used Perforated pipe is now used in some situations (linear plantings Mojave) My current research is focusing on wicks - low cost, durable

Container type The container type and planting system make a difference in irrigation choice Tall pot, half high, deep pot, plant band or supercell? Watering interval Goals for survival and growth

How efficient? My goal has been to irrigate plants with minimal water use -- perhaps a quart a month for species like mesquite This has been possible if they are also planted with a tree shelter to reduce temperatures and exposure to the wind They don’t grow much - but they survive until it rains

Restoration in remote places My goal has been to reduce water use during establishment to a low enough level to be done by hand carrying water Or using a mule, many miles from the water source

It is possible Planted 1995, photo 2008

More information A wide range of papers and web sites Try ecocomposite.org Sakia.org And for more information on desert Restoration

June 2007

You Can Help Try these systems -- figure out how to make them better, cheaper and more efficient Find out what works and what doesn’t and let me know Send money to support research Buy my book on desert and dryland restoration and send it to a library or university in Africa, Mexico, Asia

Thanks To friends, students (AIU, SDSU, UCR, WCIU), staff, funders, vendors and family who have helped along the way To the traditional farmers who figured most of this out -- and shared information and ideas freely Special thanks to Steve Mitchell, Wes Jarrell, Ross Virginia, Mike Allen and John Rieger who made this possible And to the many scientists and extension specialists who have provided insight and descriptions of traditional irrigation systems